Smooth muscle cell proliferation initiates intimal hyperplasia, a response to vessel wall injury. After wall injury, platelets accumulate on the injured surface and release lysophosphatidic acid (LPA) which inhibits PKA thereby regulating CREB/CREM/ICER. Understanding the regulation of CREB/CREM/ICER is important as it affects smooth muscle cell proliferation. In this proposal, I plan to investigate the regulation of CREB/CREM/ICER by LPA as it pertains to AP-1 transcription and smooth muscle cell proliferation. Ultimately, this information will be used in the development of therapeutic intervention to address the clinically relevant problem of vessel restenosis caused by intimal hyperplasia.